Sen. Bernie Sanders, I-Vt., condemned a new advertisement from President Trump’s reelection campaign that blamed Democrats for the deaths of any U.S. citizens at the hands of undocumented immigrants as “so sad for our country.”

The advertisement, titled “Complicit,” was released on the anniversary of Trump’s inauguration, and hours into the government shutdown that resulted from the unresolved standoff over immigration reform. “Democrats who stand in our way will be complicit in every murder committed by illegal immigrants,” the ad says.

On CNN’s “State of the Union” Sunday morning, Sanders said it was “really unbelievable” that the president of the United States would say “such nonsense” and make “such outrageous statements.”

Sanders is calling for the government to reopen as soon as possible, but said he will not vote for any funding bill that does not help people previously protected from deportation by the Deferred Action for Childhood Arrivals program (DACA), which Trump ended in September. The Trump administration has accused liberals like Sanders of “holding lawful citizens hostage over their demands for amnesty for illegal immigrants.”

The former Democratic presidential candidate cited polls by CNN and CBS that found that a majority of Americans believe that the so-called “Dreamers,” who came into the United States illegally as children, should be given a chance to obtain legal status.

Sen. Bernie Sanders speaks at a rally on Capitol Hill in support of DACA and before the government shut down on Jan. 19. (Photo: Jose Luis Magana/AP)

“They need a path towards citizenship. That’s not my view. That is the overwhelming view of the American people. Then you see a president put stuff like that on the air trying to divide us up, trying to foment hatred? It is — it is really sad,” Sanders told CNN anchor Jake Tapper.

Sanders strongly criticized the administration’s threat to deport the roughly 800,000 young people protected by the Obama-era executive action. “Let me say this,” he said. “If we allow Trump to get away with what he did — and that is, repeal the executive order on DACAs — and if these 800,000 people, young people, are subjected to deportation, this will be one of the ugliest stains in the history of the United States.”

The advertisement, however, does not specifically address the DACA issue. The short video focuses on Luis Bracamontes, a Mexican citizen living illegally in the United States, who murdered two Sacramento police officers in 2014, to justify Trump’s proposed immigration policies: building a wall along the U.S.-Mexico border, deporting criminals and stopping illegal immigration.

When asked if Sanders would be willing to vote for the construction of a border wall if Republicans offered a pathway to citizenship for the “dreamers,” he said, “It’s something — look, I think the wall was a great idea in the 15th century, when the Chinese built the Great China Wall. I don’t think it makes a whole lot of sense now. But I’m willing to sit down in a room and do what the American people want.” Sanders then reiterated his belief that American voters favor making it possible for the Dreamers to become citizens.